Breast cancer is the most common cancer among women, accounting for one third of cancer diagnosis in the United States. Eradication of breast cancer is likely to require a partnership of diverse scientific disciplines and training of new breed of basic and translational researchers. The goal of this training grant is to train 6 postdoctoral fellows (including MD and PhD) to perform state-of-the-art research in hormonal regulation, signal transduction, cell cycle controls, cell structure and motility, and experimental therapeutics applied to breast cancer. The strength of the proposed grant is the training faculty. Drawn from both basic science departments and clinical departments (including Braman Family Breast Cancer Institute and Sylvester Comprehensive Cancer Center), the 13 faculty members are an excellent group whose well-funded research comprises a cross-section of structural, molecular and cell biological, basic and translational science approaches to breast cancer research. The faculty members have extensive experience in training graduate students and postdoctoral fellows (including MD/PhD) who have gone onto become successful independent researchers. The overall goal of this program is to provide guidance for trainees to acquire unique research skills and to mold their intellectual rigor to sustain an independent, clinically-informed research career in breast cancer. All trainees are required to attend formal didactic courses, symposia, breast cancer research seminars, grand rounds, workshops, journal clubs and an annual retreat, which provide forum for exchange of ideas and interaction among different disciplines. Progress of the trainee's research will be closely monitored in bi-weekly data reviews. Thus this training program fulfills a serious national need for breast cancer researchers with ample knowledge in basic, clinical and translational research. The proposed program has many unique strengths including : 1) the existence of a specialized breast cancer research institute (Braman Family Breast Cancer Institute) and a well-known cancer center (Sylvester Comprehensive Cancer Center), 2) the research productivity, research funding, training experience, and administrative capability and experience of program faculty in general and the program directors in particular, and 3) the opportunity and availability of infrastructure for fostering continued interactions between clinical and basic research in breast cancer.